Witnesses in western Kenya say fighting between army troops and rebel militia forces has killed at least three people in the volatile Mount Elgon region.

Several hundred people have fled the area near the Kenyan-Ugandan border since the army launched attacks against the rebels on Monday. Witnesses say army helicopters are dropping bombs while soldiers are rounding up local residents in a search for militiamen.

A former lawmaker from the district criticized the government operation, calling it a serious human tragedy.

The government says its operation is aimed at subduing several militias, including the Sabaot Land Defense Force. Officials blame the group for killing many locals, including 13 people shot, burned or hacked to death last week in attacks on two villages.

Mount Elgon has been plagued by deadly clan-based land disputes for years, well before the disputed presidential election in December that plunged Kenya into weeks of ethnic violence.